In kidney transplantation, immunologically-mediated rejection remains the most common cause of allograft failure. New technology has resulted in significant advances in our ability to prevent and treat rejection. These include development of antibodies which can block immune responses at very specific points. This prospective, randomized, double-blind study will evaluate the ability of a new monoclonal antibody (HAT), Humanized Anti-Tac, Hoffman-LaRoche, Inc) to reduce rejection episodes when administered along with standard three-drug immunosuppressive therapy in kidney transplant recipients. Prior to transplant surgery, recipients of first cadaveric transplants will be randomized to one of two treatment arms. The first will receive a single dose of HAT (1 mg/kg) before transplantation, with subsequent doses administered on an outpatient basis at 14, 28, 42, and 56 days posttransplant. Those randomized to the second arm will receive a placebo infusion at the same intervals. In addition to the study drug, both groups will receive standard three-drug (cyclosporine, azathioprine, prednisone) immunosuppression. The primary endpoint is incidence of acute rejection within the first 6 months posttransplant. It is anticipated that the initial dose of HAT will be given as an inpatient at UAB Hospital, with subsequent doses administered as an outpatient in the GCRC.